[go: up one dir, main page]

EP1202043B1 - Fotoelectric measuring device - Google Patents

Fotoelectric measuring device Download PDF

Info

Publication number
EP1202043B1
EP1202043B1 EP00126446A EP00126446A EP1202043B1 EP 1202043 B1 EP1202043 B1 EP 1202043B1 EP 00126446 A EP00126446 A EP 00126446A EP 00126446 A EP00126446 A EP 00126446A EP 1202043 B1 EP1202043 B1 EP 1202043B1
Authority
EP
European Patent Office
Prior art keywords
polarization
measured
sensor
filter
measuring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP00126446A
Other languages
German (de)
French (fr)
Other versions
EP1202043A1 (en
Inventor
Hans Pallingen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
X Rite Inc
Original Assignee
X Rite Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by X Rite Inc filed Critical X Rite Inc
Publication of EP1202043A1 publication Critical patent/EP1202043A1/en
Application granted granted Critical
Publication of EP1202043B1 publication Critical patent/EP1202043B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/21—Polarisation-affecting properties

Definitions

  • the invention relates to a measuring device for the photoelectric measurement of a test object according to the preamble of independent claim 1.
  • the invention relates to a densitometer or a colorimeter.
  • Densitometric meters and systems are often equipped with polarizing filters. Measurements with a polarizing filter result in a smaller ink density decrease during drying of the printing ink and an extended range over which the color density is linearly related to the layer thickness of the printing ink.
  • the printer has a great deal of interest in obtaining readings as long as possible before the ink has dried to limit rejects. This requires a polarization device.
  • the purpose of the polarization filter is to suppress the surface reflection of the wet pressure. Two polarization filters are used for this purpose.
  • the first polarization filter is located in the beam path of the light source and thus allows only one oscillation plane. These aligned light rays are partially reflected by the color surface without the vibration level changing.
  • a second polarizing filter lies in the beam path of the sensor and is rotated 90 ° with respect to the first filter so that the polarized light beams reflected on a smooth surface can not pass this second polarizing filter or at least only partially pass through this second polarizing filter.
  • the amount of light resulting from the surface gloss is strongly or ideally suppressed completely, and the sensor essentially measures only the unpolarized light component.
  • the measured value refers to the human eye. Since measurements with polarizing filters do not correlate with the observer's impression, the standards prescribe color measurements without polarization filters.
  • the JP 02-189 408 A describes an adhesive tape detecting device for detecting an adhesive tape.
  • the adhesive tape detection device has a variable filter.
  • the DE 195 30 185 A describes a color measuring device for offset printing.
  • US 5,892,612 A and US 5,469,279 A describe light switches where incident light is either blocked or absorbed (dark) or (partially) transmitted (light).
  • the CH 659 135 A describes a method and apparatus for calibrating a densitometer equipped with polarizers.
  • the AU-39046/89 B describes a measuring device for both densitometric and colorimetric measurement of a measuring object with a single optical measuring head, which allows both measurements with coming from the measuring object in a single direction light.
  • the present invention is intended to improve a measuring device of the generic type in such a way that the filtering of the highlight portion is purely electronic, i. can be activated or deactivated without mechanical movement of polarizing filters or other components of the measuring device.
  • At least one of the two polarization filters is formed electronically controllable and is acted upon by the control electronics with appropriate control voltages.
  • Measuring device designated M as a whole is designed as a remission measuring device and comprises, in a manner known per se, a light source consisting of (in the example two) lamps 1 and 2, a measuring objective 3, a photoelectric sensor 4 and an electronic control unit 5. Further, between the lamps 1 and 2 and the measurement object 6 to be measured, a first polarization filter 8 and a second polarization filter 9 are provided between the measurement object 6 and the measurement objective 3.
  • the lamps 1 and 2 illuminate a measuring field 7 of a measuring object 6 to be measured below 45 ° via the first polarizing filter 8, and the measuring objective 3 captures the measuring light remitted by the measuring object and transmitted by the second polarization filter 9 below 0 °
  • the control electronics 5 converts the analog electrical signals corresponding to the intensity of the received light generated by the sensor 4 into corresponding digital measured values and then calculates the desired measured variables or makes the digital measured values available to an external computer for further processing ,
  • the measuring device according to the invention corresponds to conventional measuring devices of this type, so that the expert in this regard requires no further explanation.
  • At least one of the two polarizing filters 8 and 9, in the example shown the second polarizing filter 9, is designed according to the invention as an electronically controllable polarization filter. It is realized by one or more polarizing liquid crystal layers whose polarization plane is rotated by 90 ° under the influence of an electric field can. Suitable liquid crystals and technologies are, for example, those used in the known liquid crystal displays (LCD). Particularly suitable are so-called. Twisted Nematic liquid crystals, because they rotate the plane of polarization when applied to an electrical voltage by exactly 90 °.
  • the control electronics 5 provides the control voltage required for driving the second polarization filter 9. In this way, the rotation of the polarization plane and thus the activation or deactivation of the gloss suppression by applying suitable electrical signals in a purely electronic way can be done very easily and quickly.
  • the switching can be triggered manually via control buttons 51 or programmatically.
  • the polarizing filter 9 may comprise two or more liquid crystal layers connected in series, as shown in the schematic sectional view of FIG. 2 is clarified.
  • the second polarizing filter 9 here comprises two liquid crystal layers 91 and 92 sandwiched between three transparent electrodes 93-95.
  • the three electrodes are connected to the control electronics 5 and are acted upon by this in a conventional manner with appropriate switching voltages.
  • the measuring device shown can be designed in a manner known per se as a densitometer or colorimeter.

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Spectrometry And Color Measurement (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)

Description

Die Erfindung betrifft eine Messvorrichtung zur fotoelektrischen Ausmessung eines Messobjekts gemäß dem Oberbegriff des unabhängigen Anspruchs 1. Insbesondere betrifft die Erfindung ein Densitometer oder ein Farbmessgerät.The invention relates to a measuring device for the photoelectric measurement of a test object according to the preamble of independent claim 1. In particular, the invention relates to a densitometer or a colorimeter.

Densitometrische Meßgeräte und -systeme sind häufig mit Polarisationsfiltern ausgestattet. Bei Messungen mit Polarisationsfilter ergibt sich ein geringerer Farbdichterückgang während der Trocknung der Druckfarbe und ein erweiterter Bereich, über welchen die Farbdichte mit der Schichtdicke der Druckfarbe linear zusammenhängt. Wenn das Messergebnis zur Maschinensteuerung im Druck dient, hat der Drucker ein grosses Interesse möglichst lange, bevor die Farbe getrocknet ist, schon Messwerte zu erhalten, um Ausschuss einzuschränken. Dazu ist eine Polarisationseinrichtung notwendig.Densitometric meters and systems are often equipped with polarizing filters. Measurements with a polarizing filter result in a smaller ink density decrease during drying of the printing ink and an extended range over which the color density is linearly related to the layer thickness of the printing ink. When the measurement result is used to control the machine in print, the printer has a great deal of interest in obtaining readings as long as possible before the ink has dried to limit rejects. This requires a polarization device.

Nasse Druckfarben haben eine glänzende Oberfläche, beim Trocknen passt sich die Druckfarbe der Oberflächenstruktur des Papiers an und wird abhängig von der Papierqualität mehr oder weniger matt. Daraus ergeben sich unterschiedliche Messergebnisse vor und nach dem Trocknen. Sinn der Polarisationsfilter ist es, die Oberflächenspiegelung des nassen Drucks zu unterdrücken. Dazu werden zwei Polarisationsfilter verwendet. Der erste Polarisationsfilter liegt im Strahlengang der Lichtquelle und lässt so nur eine Schwingungsebene durch. Diese ausgerichteten Lichtstrahlen werden von der Farboberfläche teilweise spiegelnd reflektiert, ohne dass sich die Schwingungsebene ändert. Ein zweiter Polarisationsfilter liegt im Strahlengang des Sensors und ist bezüglich des ersten Filters um 90° gedreht, sodass die auf einer glatten Oberfläche reflektierten polarisierten Lichtstrahlen diesen zweiten Polarisationsfilter nicht passieren können oder zumindest nur teilweise von diesem zweiten Polarisationsfilter durchgelassen werden. Somit wird der vom Oberflächenglanz herrührende Lichtanteil stark oder ideal ganz unterdrückt, und der Sensor misst im wesentlichen nur den unpolarisierten Lichtanteil.Wet printing inks have a glossy surface, while drying, the ink adapts to the surface texture of the paper and becomes more or less dull depending on the paper quality. This results in different measurement results before and after drying. The purpose of the polarization filter is to suppress the surface reflection of the wet pressure. Two polarization filters are used for this purpose. The first polarization filter is located in the beam path of the light source and thus allows only one oscillation plane. These aligned light rays are partially reflected by the color surface without the vibration level changing. A second polarizing filter lies in the beam path of the sensor and is rotated 90 ° with respect to the first filter so that the polarized light beams reflected on a smooth surface can not pass this second polarizing filter or at least only partially pass through this second polarizing filter. Thus, the amount of light resulting from the surface gloss is strongly or ideally suppressed completely, and the sensor essentially measures only the unpolarized light component.

Bei farbmetrischen Meßsystemen bezieht sich der Messwert auf das menschliche Auge. Da Messungen mit Polarisationsfiltern nicht mit dem Eindruck des Beobachters korrelieren, schreiben die Normen Farbmessungen ohne Polarisationsfilter vor.In colorimetric measuring systems, the measured value refers to the human eye. Since measurements with polarizing filters do not correlate with the observer's impression, the standards prescribe color measurements without polarization filters.

Viele moderne Messgeräte bieten beide Messmöglichkeiten, nämlich Dichtemessungen und farbmetrische Messungen, z.B. gemäß CIEL*a*b* oder CIEL*u*v*.Many modern measuring instruments offer both measurement options, namely density measurements and colorimetric measurements, eg according to CIEL * a * b * or CIEL * u * v *.

Die JP 02-189 408 A beschreibt eine Klebeband-Detektionsvorrichtung, um ein Klebeband zu detektieren. Die Klebeband-Detektionsvorrichtung weist einen variablen Filter auf.The JP 02-189 408 A describes an adhesive tape detecting device for detecting an adhesive tape. The adhesive tape detection device has a variable filter.

Die DE 195 30 185 A beschreibt eine Farbmesseinrichtung fiir den Offsetdruck.The DE 195 30 185 A describes a color measuring device for offset printing.

Die US-5,892,612 A und US-5,469,279 A beschreiben Lichtschalter, bei denen einfallendes Licht entweder gesperrt bzw. absorbiert (dunkel) oder (teilweise) durchgelassen (hell) wird.The US 5,892,612 A and US 5,469,279 A describe light switches where incident light is either blocked or absorbed (dark) or (partially) transmitted (light).

Die CH 659 135 A beschreibt ein Verfahren und Vorrichtung zur Eichung eines mit Polarisatoren ausgerüsteten Densitometers.The CH 659 135 A describes a method and apparatus for calibrating a densitometer equipped with polarizers.

Die AU-39046/89 B beschreibt eine Messvorrichtung sowohl zum densitometrischen als auch zum farbmetrischen Ausmessen eines Messobjekts mit einem einzelnen optischen Messkopf, der beide Messungen mit vom Messobjekt in einer einzigen Richtung kommendem Licht ermöglicht.The AU-39046/89 B describes a measuring device for both densitometric and colorimetric measurement of a measuring object with a single optical measuring head, which allows both measurements with coming from the measuring object in a single direction light.

ZUSAMMENFASSUNG DER ERFINDUNGSUMMARY OF THE INVENTION

Ausgehend von diesem Stand der Technik soll durch die vorliegende Erfindung eine Messvorrichtung der gattungsgemäßen Art dahingehend verbessert werden, dass die Ausfilterung des Glanzlichtanteils rein elektronisch, d.h. ohne mechanische Bewegung von Polarisationsfiltern oder anderen Komponenten der Messvorrichtung aktiviert bzw. deaktiviert werden kann.Based on this prior art, the present invention is intended to improve a measuring device of the generic type in such a way that the filtering of the highlight portion is purely electronic, i. can be activated or deactivated without mechanical movement of polarizing filters or other components of the measuring device.

Die Lösung dieser der Erfindung zugrundeliegenden Aufgaben ergibt sich durch die erfindungsgemäße Messvorrichtung gemäß den kennzeichnenden Merkmalen des unabhängigen Anspruchs 1. Besonders zweckmäßige und vorteilhafte Ausgestaltungen sind Gegenstand der abhängigen Ansprüche.The solution of this problem underlying the invention results from the inventive measuring device according to the characterizing features of independent claim 1. Particularly expedient and advantageous embodiments are the subject of the dependent claims.

Gemäß dem grundlegenden Hauptaspekt der vorliegenden Erfindung ist also wenigstens einer der beiden Polarisationsfilter elektronisch steuerbar ausgebildet und wird von der Steuerelektronik mit passenden Steuerspannungen beaufschlagt. Dadurch kann die Drehung der Polarisationsebene und damit die Aktivierung bzw. Deaktivierung der Glanzunterdrückung durch Anlegen geeigneter elektrischer Signale auf rein elektronischem Wege sehr einfach und schnell erfolgen.According to the basic basic aspect of the present invention, therefore, at least one of the two polarization filters is formed electronically controllable and is acted upon by the control electronics with appropriate control voltages. As a result, the rotation of the polarization plane and thus the activation or deactivation the gloss suppression by applying suitable electrical signals in a purely electronic way very easy and fast.

Im folgenden wird die Erfindung anhand der Zeichnung näher erläutert. Es zeigen:

Fig. 1
ein Prinzipschema eines typischen Ausführungsbeispiels der erfindungsgemässen Messvorrichtung und
Fig. 2
einen schematischen Schnitt durch einen Polarisationsfilter der Messvorrichtung der Figur 1.
In the following the invention will be explained in more detail with reference to the drawing. Show it:
Fig. 1
a schematic diagram of a typical embodiment of the inventive measuring device and
Fig. 2
a schematic section through a polarizing filter of the measuring device of FIG. 1 ,

Die in Fig. 1 als Ganze mit M bezeichnete Messvorrichtung ist als Remissionsmessgerät ausgebildet und umfasst in an sich bekannter Weise eine aus (im Beispiel zwei) Lampen 1 und 2 bestehende Lichtquelle, ein Messobjektiv 3, einen fotoelektrischen Sensor 4 und eine Steuerelektronik 5. Ferner ist zwischen den Lampen 1 und 2 und dem auszumessenden Messobjekt 6 ein erster Polarisationsfilter 8 und zwischen dem Messobjekt 6 und dem Messojektiv 3 ein zweiter Polarisationsfilter 9 vorgesehen. Wie bei Messgeräten dieser Art üblich, beleuchten die Lampen 1 und 2 über den ersten Polarisationsfilter 8 ein Messfeld 7 eines auszumessenden Messobjekts 6 unter 45°, und das Messobjektiv 3 fängt das vom Messobjekt remittierte und vom zweiten Poalrisationsfilter 9 durchgelassene Messlicht unter 0° auf und beaufschlagt damit den Sensor 4. Die Steuerelektronik 5 wandelt die vom Sensor 4 erzeugten, der Intensität des empfangenen Lichts entsprechenden analogen elektrischen Signale in entsprechende digitale Messwerte um und berechnet daraus dann die gewünschten Messgrössen oder stellt die digitalen Messwerte einem externen Rechner zur weiteren Verarbeitung zur Verfügung.In the Fig. 1 Measuring device designated M as a whole is designed as a remission measuring device and comprises, in a manner known per se, a light source consisting of (in the example two) lamps 1 and 2, a measuring objective 3, a photoelectric sensor 4 and an electronic control unit 5. Further, between the lamps 1 and 2 and the measurement object 6 to be measured, a first polarization filter 8 and a second polarization filter 9 are provided between the measurement object 6 and the measurement objective 3. As usual with measuring devices of this type, the lamps 1 and 2 illuminate a measuring field 7 of a measuring object 6 to be measured below 45 ° via the first polarizing filter 8, and the measuring objective 3 captures the measuring light remitted by the measuring object and transmitted by the second polarization filter 9 below 0 ° The control electronics 5 converts the analog electrical signals corresponding to the intensity of the received light generated by the sensor 4 into corresponding digital measured values and then calculates the desired measured variables or makes the digital measured values available to an external computer for further processing ,

Soweit entspricht die erfindungsgemäße Messvorrichtung herkömmlichen Messvorrichtungen dieser Art, so dass der Fachmann diesbezüglich keiner näheren Erläuterung bedarf.As far as the measuring device according to the invention corresponds to conventional measuring devices of this type, so that the expert in this regard requires no further explanation.

Der erfindungswesentliche Unterschied zum Stand der Technik besteht in der Ausbildung des bzw. der Polarisationsfilter 8 und/oder 9. Mindestens einer der beiden Polarisationsfilter 8 und 9, im gezeigten Beispiel der zweite Polarisationsfilter 9, ist gemäss der Erfindung als elektronisch steuerbarer Polarisationsfilter ausgebildet. Er ist dazu durch eine oder mehrere polarisierende Flüssigkristallschichten realisiert, deren Polarisationsebene unter dem Einfluss eines elektrischen Felds um 90° gedreht werden kann. Geeignete Flüssigkristalle und Technologien sind z.B. solche, wie sie in den bekannten Flüssigkristallanzeigen (Liquid Crystal Diplay, LCD) verwendet werden. Besonders geeignet sind sog. Twisted Nematic Flüssigkristalle, weil sie die Polarisationsebene bei Anliegen einer elektrischen Spannung um genau 90° drehen.At least one of the two polarizing filters 8 and 9, in the example shown the second polarizing filter 9, is designed according to the invention as an electronically controllable polarization filter. It is realized by one or more polarizing liquid crystal layers whose polarization plane is rotated by 90 ° under the influence of an electric field can. Suitable liquid crystals and technologies are, for example, those used in the known liquid crystal displays (LCD). Particularly suitable are so-called. Twisted Nematic liquid crystals, because they rotate the plane of polarization when applied to an electrical voltage by exactly 90 °.

Die Steuerelektronik 5 stellt die für die Ansteuerung des zweiten Polarisationsfilters 9 erforderliche Steuerspannung zur Verfügung. Auf diese Weise kann die Drehung der Polarisationsebene und damit die Aktivierung bzw. Deaktivierung der Glanzunterdrückung durch Anlegen geeigneter elektrischer Signale auf rein elektronischem Wege sehr einfach und schnell erfolgen. Die Umschaltung kann dabei manuell über Bedienungsknöpfe 51 oder programmgesteuert ausgelöst werden.The control electronics 5 provides the control voltage required for driving the second polarization filter 9. In this way, the rotation of the polarization plane and thus the activation or deactivation of the gloss suppression by applying suitable electrical signals in a purely electronic way can be done very easily and quickly. The switching can be triggered manually via control buttons 51 or programmatically.

Ein wesentliches Kriterium der Qualität der Polarisation ist, wie stark der (polarisierte) Lichtanteil, der nicht in der Polarisationsebene des zweiten Polarisationsfilters 9 liegt, unterdrückt wird. Um die Qualität des Flüssigkristall-Polarisationsfilters 9 diesbezüglich zu erhöhen, kann der Polarisationsfilter 9 dazu zwei oder mehrere hintereinandergeschaltete Flüssigkristallschichten aufweisen, wie dies anhand der schematischen Schnittdarstellung der Figur 2 verdeutlicht ist.An essential criterion of the quality of the polarization is how strongly the (polarized) light component, which is not in the polarization plane of the second polarization filter 9, is suppressed. In order to increase the quality of the liquid crystal polarizing filter 9 in this regard, the polarizing filter 9 may comprise two or more liquid crystal layers connected in series, as shown in the schematic sectional view of FIG FIG. 2 is clarified.

Der zweite Polarisationsfilter 9 umfasst hier zwei Flüssigkristallschichten 91 und 92, die zwischen drei transparenten Elektroden 93-95 eingeschlossen sind. Die drei Elektroden sind an dei Steuerelektronik 5 angeschlossen und werden von dieser in an sich bekannter Weise mit passenden Schaltspannungen beaufschlagt.The second polarizing filter 9 here comprises two liquid crystal layers 91 and 92 sandwiched between three transparent electrodes 93-95. The three electrodes are connected to the control electronics 5 and are acted upon by this in a conventional manner with appropriate switching voltages.

Durch Ergänzung um farbselektive und/oder spektral auflösende optische Komponenten kann die gezeigte Messvorrichtung in an sich bekannter Weise als Densitometer oder Farbmessgerät ausgebildet werden.By supplementing with color-selective and / or spectrally resolving optical components, the measuring device shown can be designed in a manner known per se as a densitometer or colorimeter.

Claims (3)

  1. An instrument for the densitometric and colorimetric measurement of an object to be measured, with a light source (1, 2) for acting upon the object to be measured (6) with measuring light, with a polarization filter (8) arranged between the light source (1, 2) and the object to be measured (6), a photoelectric sensor (4), a second polarization filter (9) situated between the object to be measured (6) and the photoelectric sensor (4), a measuring lens (3) which conveys the measuring light starting from a measurement spot of the object to be measured (6) to the sensor (4) by way of the second polarization filter (9), and with means to rotate the polarization plane of one of the two polarization filters substantially through 90° relative to that of the other one of the two polarization filters, and with an electronic control means (5) co-operating with the sensor (4) for processing the electrical signals produced by the latter, wherein at least one of the two polarization filters (8, 9) is designed so as to be controllable electronically, wherein the polarization plane thereof is capable of being rotated by the electronic control means (5), and wherein at least one of the two polarization filters (8, 9) has a polarizing medium in the form of at least one liquid-crystal layer (91, 92), the polarization plane of which can be rotated through preferably 90° under the influence of an electrical field.
  2. An instrument according to claim 1, wherein the at least one liquid-crystal layer comprises so-called twisted nematic liquid crystals.
  3. An instrument according to one of the preceding claims, wherein only the second polarization filter (9) situated between the object to be measured (6) and the sensor (4) is designed so as to be controllable electronically.
EP00126446A 2000-10-26 2000-12-06 Fotoelectric measuring device Expired - Lifetime EP1202043B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
ITBZ000044 2000-10-26
IT2000BZ000044A IT1316145B1 (en) 2000-10-26 2000-10-26 PHOTOELECTRIC MEASUREMENT DEVICE EQUIPPED WITH A DIPOLARIZATION FILTER.
CA002390744A CA2390744A1 (en) 2000-10-26 2002-06-14 Photoelectric measuring device
US10/177,714 US7023548B2 (en) 2000-10-26 2002-06-21 Photoelectric measuring device

Publications (2)

Publication Number Publication Date
EP1202043A1 EP1202043A1 (en) 2002-05-02
EP1202043B1 true EP1202043B1 (en) 2011-02-09

Family

ID=32995171

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00126446A Expired - Lifetime EP1202043B1 (en) 2000-10-26 2000-12-06 Fotoelectric measuring device

Country Status (4)

Country Link
US (1) US7023548B2 (en)
EP (1) EP1202043B1 (en)
CA (1) CA2390744A1 (en)
IT (1) IT1316145B1 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2014257297B2 (en) * 2013-04-21 2018-04-05 Mobileodt Ltd A polarized light imaging apparatus and methods thereof for separating light from a surface of a sample its deeper diffuse layers
DE102013109005A1 (en) * 2013-08-20 2015-02-26 Khs Gmbh Device and method for identifying codes under film
US10379388B2 (en) * 2016-08-12 2019-08-13 Avegant Corp. Digital light path length modulation systems
US10516879B2 (en) 2016-08-12 2019-12-24 Avegant Corp. Binocular display with digital light path length modulation
US10057488B2 (en) 2016-08-12 2018-08-21 Avegant Corp. Image capture with digital light path length modulation
US10809546B2 (en) 2016-08-12 2020-10-20 Avegant Corp. Digital light path length modulation
US10401639B2 (en) 2016-08-12 2019-09-03 Avegant Corp. Method and apparatus for an optical path length extender
US10187634B2 (en) 2016-08-12 2019-01-22 Avegant Corp. Near-eye display system including a modulation stack
US10185153B2 (en) 2016-08-12 2019-01-22 Avegant Corp. Orthogonal optical path length extender
US11995567B2 (en) * 2020-08-27 2024-05-28 Micron Technology, Inc. Apparatuses and methods for color matching and recommendations

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH532261A (en) * 1970-12-04 1972-12-31 Hoffmann La Roche Light control cell

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2141364C3 (en) * 1971-08-18 1981-02-19 Sulzer Morat Gmbh, 7024 Filderstadt Method and device for recognizing the color of an original
US4003660A (en) * 1975-12-03 1977-01-18 Hunter Associates Laboratory, Inc. Sensing head assembly for multi-color printing press on-line densitometer
ATE20620T1 (en) * 1982-04-10 1986-07-15 Hell Rudolf Dr Ing Gmbh METHOD AND DEVICE FOR MEASUREMENT OF THE DENSITY OF INK LAYERS WHILE WET PRINTING INK.
CH659135A5 (en) 1982-10-29 1986-12-31 Gretag Ag Method and appliance for calibrating a densitometer equipped with polarisers
US4670744A (en) * 1985-03-14 1987-06-02 Tektronix, Inc. Light reflecting three-dimensional display system
DK163837C (en) * 1987-11-10 1994-09-05 Neltec As DEVICE FOR COLOR CONTROL OF OBJECTS
DE3830731A1 (en) 1988-09-09 1990-03-22 Heidelberger Druckmasch Ag DEVICE FOR COLOR MEASUREMENT
JPH02189408A (en) 1989-01-18 1990-07-25 Hitachi Ltd Adhesive tape detector
US5469279A (en) 1989-10-30 1995-11-21 The University Of Colorado Foundation, Inc. Chiral smectic liquid crystal multipass optical filters including a variable retarder (and a variable isotropic spacer)
DE9415117U1 (en) 1994-09-17 1994-12-22 Fuchs, Annette, Dr.-Ing., 63571 Gelnhausen Non-contact spectral densitometric colorimeter
IL115915A (en) * 1994-11-10 1999-12-22 Lawrence B Wolff Method and apparatus for viewing
JPH09224127A (en) * 1996-02-15 1997-08-26 Canon Inc Document density detector
US5785041A (en) * 1996-03-26 1998-07-28 Hologic Inc. System for assessing bone characteristics
DE19617009C2 (en) * 1996-04-27 1999-05-20 Roland Man Druckmasch Photoelectric measuring device
US6055053A (en) * 1997-06-02 2000-04-25 Stress Photonics, Inc. Full field photoelastic stress analysis
US5892612A (en) 1997-08-07 1999-04-06 Cambridge Research & Instrumentation Inc. Tunable optical filter with white state
US5963332A (en) * 1997-08-20 1999-10-05 General Electric Company Internal color probe
CA2359835A1 (en) * 2000-10-26 2002-04-26 Viptronic Gmbh Photo electric measuring device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH532261A (en) * 1970-12-04 1972-12-31 Hoffmann La Roche Light control cell

Also Published As

Publication number Publication date
ITBZ20000044A1 (en) 2002-04-26
US20030234930A1 (en) 2003-12-25
EP1202043A1 (en) 2002-05-02
IT1316145B1 (en) 2003-03-28
US7023548B2 (en) 2006-04-04
CA2390744A1 (en) 2003-12-14

Similar Documents

Publication Publication Date Title
DE3603235A1 (en) DEVICE AND METHOD FOR ANALYZING PARAMETERS OF A FIBROUS SUBSTRATE
DE3322870C2 (en) Optoacoustic measuring device for determining a particle concentration
EP1202043B1 (en) Fotoelectric measuring device
DE69713286T2 (en) SUBMICRON RESOLUTION IMAGE SYSTEM WITH TUNABLE ACUSTO-OPTICAL FILTER
DE3741940C2 (en) Color sensor
DE19636711B4 (en) Improvements to or regarding spectrometers
DE69000227T2 (en) METHOD AND DEVICE FOR DETECTING AND MEASURING A PHYSICAL SIZE.
WO2021058260A1 (en) Spectrometer device and method for calibrating a spectrometer device
DE2853458A1 (en) METHOD AND DEVICE FOR MEASURING THE BRIGHTNESS OF GRIND PRODUCTS OF A MILL, ESPECIALLY FLOUR
DE102004003615B4 (en) Apparatus and method for detecting and evaluating an image from a predetermined section of a printed product
DE4109744C2 (en) Method for determining the area coverage of a printing template, in particular a printing plate, and device for performing the method
DE3314333A1 (en) METHOD AND DEVICE FOR REGULATING THE INPUT TO THE INKS OF A MULTI-COLOR PRINTING MACHINE
DE3509163C2 (en) Method and device for measuring the elongation of materials under tension
DE4237004A1 (en) On=line offset printing colour applicator control system - uses calculated colour values over part of printed sheet to derive integrated comparison level
EP0768178B1 (en) Process for detecting layers on metallic surfaces in printing machines
DE112005002618T5 (en) Double calculation of polymer films and the like
DE3883058T2 (en) Optical sensor.
AT525942B1 (en) Method and device for VCD analysis of an analyte
DE2651003A1 (en) METHOD AND DEVICE FOR MEASURING THE THICKNESS OF A TRANSPARENT MATERIAL ON A BASE ELEMENT
DE2130165C3 (en) Method and device for determining the ratio of the unprinted to the printed area of an original
DE1803318A1 (en) Equipment and method for measuring optical dichroism
EP1714121A1 (en) Filter unit with an adjustable wavelength and assembly comprising said filter unit
DE102020216450A1 (en) Device and method for detecting at least one substance
DE2612513C2 (en) Beam switch
DE1773489C3 (en) Device for the dry weight measurement of running webs

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

Kind code of ref document: A1

Designated state(s): CH DE FR GB IT LI

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20021008

AKX Designation fees paid

Free format text: CH DE FR GB IT LI

APBN Date of receipt of notice of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA2E

APBR Date of receipt of statement of grounds of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA3E

APAF Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNE

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: X-RITE, INC.

APBT Appeal procedure closed

Free format text: ORIGINAL CODE: EPIDOSNNOA9E

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: X-RITE, INCORPORATED

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE FR GB IT LI

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: CH

Ref legal event code: NV

Representative=s name: FREI PATENTANWALTSBUERO AG

REF Corresponds to:

Ref document number: 50016069

Country of ref document: DE

Date of ref document: 20110324

Kind code of ref document: P

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 50016069

Country of ref document: DE

Effective date: 20110324

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20111110

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 50016069

Country of ref document: DE

Effective date: 20111110

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20131218

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20131220

Year of fee payment: 14

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20150831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20141231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20141206

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20161221

Year of fee payment: 17

Ref country code: DE

Payment date: 20161213

Year of fee payment: 17

Ref country code: GB

Payment date: 20161222

Year of fee payment: 17

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 50016069

Country of ref document: DE

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20171206

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180703

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171231

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171206

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171231